<p>Performs the given steps in parallel.</p><p>If any sub-steps in an aggregate result in an error, the aggregate step as a
whole is considered to have errored.</p><p>Similarly, when aggregating <a href="task-step.html"><code>task</code></a> steps, if any
<em>fail</em>, the aggregate step will fail. This is useful for build matrixes:</p><div class="highlight"><pre class="verbatim"><span class="t"></span><span class="t"></span><span class="t"></span><span class="nv"></span><span class="py">plan</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"></span><span class="t"></span><span class="t">
</span><span class="t"></span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">get</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">some-repo</span><span class="t">
</span><span class="t"></span><span class="t"></span><span class="t"></span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">aggregate</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"></span><span class="t"></span><span class="t">
</span><span class="t">  </span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">task</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">unit-windows</span><span class="t">
</span><span class="t">    </span><span class="t"></span><span class="t"></span><span class="t"></span><span class="t"></span><span class="nv"></span><span class="py">file</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">some-repo/ci/windows.yml</span><span class="t">
</span><span class="t">  </span><span class="nv">-</span><span class="sp"> </span><span class="py">task</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">unit-linux</span><span class="t">
</span><span class="t">    </span><span class="py">file</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">some-repo/ci/linux.yml</span><span class="t">
</span><span class="t">  </span><span class="nv">-</span><span class="sp"> </span><span class="py">task</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">unit-darwin</span><span class="t">
</span><span class="t">    </span><span class="py">file</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">some-repo/ci/darwin.yml</span></pre></div><p>The <code>aggregate</code> step is also useful for performing arbitrary steps in
parallel, for the sake of speeding up the build. It is often used to fetch
all dependent resources together:</p><div class="highlight"><pre class="verbatim"><span class="t"></span><span class="t"></span><span class="t"></span><span class="nv"></span><span class="py">plan</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"></span><span class="t"></span><span class="t">
</span><span class="t"></span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">aggregate</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"></span><span class="t"></span><span class="t">
</span><span class="t">  </span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">get</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">component-a</span><span class="t">
</span><span class="t">  </span><span class="t"></span><span class="t"></span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">get</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">component-b</span><span class="t">
</span><span class="t">  </span><span class="t"></span><span class="t"></span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">get</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">integration-suite</span><span class="t">
</span><span class="t"></span><span class="t"></span><span class="t"></span><span class="pi">-</span><span class="t"></span><span class="t"> </span><span class="t"></span><span class="nv"></span><span class="py">task</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">integration</span><span class="t">
</span><span class="t">  </span><span class="t"></span><span class="t"></span><span class="t"></span><span class="t"></span><span class="nv"></span><span class="py">file</span><span class="t"></span><span class="pi">:</span><span class="t"></span><span class="t"> </span><span class="nv"></span><span class="nv">integration-suite/task.yml</span></pre></div>